1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Projet d'appui à la Sécurité Alimentaire et au Développement de Maradi ( PASADEM)

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Projet Améliorer la résilience aux changements climatiques par la diffusion de technologies de gestion intégrée Eau-Sol-Agro-Sylvo-Pastoralisme, Niger (PARC/YANA-YI)

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Projet de surveillance pastorale en Afrique subsaharienne (Départements d’Abala, de Banibangou et de Filingué), Niger (ACF / AREN) {'additional_translations': {}, 'value': 482, 'label': 'Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)', 'text': 'GREAD (GREAD) - Niger', 'template': 'raw'}

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

Comments:

This technology is a measure for sustainable land management complying with national and international standards. It is also a traditional practice for the sustainable management of the resource base for pastoralism and agriculture.

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2.1 Short description of the Technology

Definition of the Technology:

Assisted Natural Regeneration (ANR) in pastoral zones is a simple and low-cost agroforestry technique. It involves locating and preserving shoots from stumps of woody and herbaceous vegetation on communal land used for agro-pastoralism, sylvo-pastoralism or pastoralism. The aim is to accelerate the process of natural regeneration resulting from natural seedlings or from sprouting stumps inherently present in the area.

2.2 Detailed description of the Technology

Description:

Assisted Natural Regeneration (ANR) is an agroforestry technique applied in areas affected by water and wind erosion on cropped fields as well as agro-pastoral and sylvo-pastoral land. Erosion results from (i) tree felling in fields and the clearing of seedlings, (ii) over-exploitation of land, and (iii) the process of desertification. Local populations in the pastoral zone of Niger include mainly transhumant livestock keepers and/or pastoralists (Tuareg, Bororo Peulh, Arabs and Toubou) who derive their income from the use of natural resources. People in the Sahelo-Saharan region have developed local know-how about sustainable land management, notably the practice of assisted natural regeneration on land that is exclusively set aside for grazing.
The significant growth of the population is dramatically increasing pressure on natural resources. In combination with the impacts of climate change and desertification, the process of land degradation has accelerated, resulting in chronic deficits in food and forage throughout the country. Facing these multiple environmental and ecological challenges, the state and its development partners have been testing and refining the technology of ANR since the 1990s. Assisted Natural Regeneration involves accelerating the process of natural regeneration of vegetation resulting from natural seedlings or from stumps inherently present in the area. Shoots from tree stumps with living root systems grow faster than seedlings derived from seeds. In the agricultural zone, ANR is a technique suited to improved land clearing, which involves locating and preserving shoots from stumps of desirable species of woody and herbaceous vegetation during the process of opening of land for cultivation. In addition to the protection of the shoots, selected species can be planted or sown through ‘enrichment planting’. The sprouts to be protected in the fields are identified during weeding. Weak stems are pruned out and fertile conditions created for development of the plants. On sylvo-pastoral communal land this results in an increase of desirable vegetation species with the best potential for ANR. These include those with a strong ability to sprout from roots (Balanites aegyptiaca, Faidherbia albida, Bombax costatum, Cassia sieberiana, Crateva adansonii, Detarium microcarpum, etc.) or those that can be propagated by layering (Guiera senegalensis, Combretum micranthum, Pterocarpus erinaceus, etc.).
In the pastoral zone the practice was developed by livestock keepers to optimize the length of the grazing period during transhumance. Techniques employed are tree trimming, selection of the livestock routes for transhumance to enhance ANR through the movement of animals, monitoring and protection of palatable species, seeding of local forage crops in areas with low vegetative cover, and protection of particular species that enhance the development of understory vegetation.
An increasing number of development projects are trying to develop local practices of ANR, especially in the northern part of the region of Tahoua and in the southern part of the region of Agadez. The main objectives of ANR are: (i) protection of cropland through erosion control (water and wind erosion), (ii) improvement of soil fertility, (iii) production of firewood or timber, (iv) production of forage for livestock, (v) reduction of evapotranspiration, and (vi) restoration and preservation of forage resources in the pastoral zone.
The following results are expected for the agricultural and agro-sylvo-pastoral zones: (i) a significant increase of woody biomass for energy provision, forage and timber, (ii) an increase in agricultural yields, and (iii) new sources of income enabling farmers to improve their living standards. Results expected for the pastoral zone include: (i) conservation and preservation of palatable vegetation species for livestock in the grazing areas, (ii) an increase in forage resources and woody biomass, and (iii) restoration of the vegetation cover on degraded pastoral land.
ANR requires labour and hand tools (hoes and machetes). The low costs of implementation and maintenance are the major advantage of this technology; these explain the ease of adoption and the broad dissemination among agro-pastoralists and livestock keepers. However, due to the lack of regular monitoring of achievements and the weak enforcement of laws that regulate the management of forest resources, the ecological and socio-economic impacts of ANR in Niger are limited, especially in the pastoral zone.

2.3 Photos of the Technology

2.4 Videos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

2.6 Date of implementation

Indicate year of implementation:

2010

If precise year is not known, indicate approximate date:

• less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through land users' innovation
• through projects/ external interventions

Comments (type of project, etc.):

The technology is developed by livestock keepers and is part of pastoralist practices; it was implemented by agro-pastoralists in agricultural areas. Livestock keepers apply the principles of assisted natural regeneration in their regions of origin or during the transhumance, by conserving woody and herbaceous vegetation. Over the last twenty years, development projects on sustainable land management have developed this technology first in the agricultural area at field level. Then, in recent years projects are implementing the technology on sylvo-pastoral land in the agro-pastoral zones in southern Niger.

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• conserve ecosystem
• preserve/ improve biodiversity
• adapt to climate change/ extremes and its impacts
• mitigate climate change and its impacts
• create beneficial economic impact
• create beneficial social impact

3.2 Current land use type(s) where the Technology is applied

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):

• Agro-silvopastoralism

Comments:

Main animal species and products: The main animal species found in the pastoral zone are: cattle, dromedaries, sheep, goats and donkeys. In this zone, the implementation of ANR is part of the management framework for herds and forage resources. The mentioned animal species are also found in the agro-pastoral zone in the south, but with many more equine animals.

In the agro-pastoral zones, the technology is applied on land primarily used for the production of millet, sorghum, cowpea, and cash crops; it is applied on land in use for agro-sylvo-pastoralism, sylvo-pastoralism and agro-pastoralism. Several development projects combine ANR with the development of markets for wood and forage. In these areas, agriculture, livestock and the trade of agro-pastoral products (livestock, cereals) are the main activities of local populations.

In Niger ANR is applied both on an individual basis at the field level and on communal land with the participation of the entire local population. The technology can be implemented on all types of land. The objectives of ANR depend on the types of land to which it is applied.

Livestock density: In the pastoral zone of the urban municipality of Abalak, the livestock density was estimated at 50 TLU/km2 in 2016. This density is found in the northern parts of the regions of Tillabéri, Maradi and Zinder, and in the south of the region of Agadez.

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?

• Yes (Please fill out the questions below with regard to the land use before implementation of the Technology)

Comments:

Implementation of ANR on communal land requires secure land tenure to avoid any change in property rights.

3.4 Water supply

Water supply for the land on which the Technology is applied:

• mixed rainfed-irrigated

Comments:

The water supply in the pastoral zone is mainly dependent on precipitation. There is also an extensive network of pastoral wells and pumping stations in the grazing areas which are most intensively used. There is a horticultural system with irrigated crops in the valley bottoms and depressions. In the agricultural zone, irrigated and rainfed cropping alternate over the year.

3.5 SLM group to which the Technology belongs

• agroforestry
• pastoralism and grazing land management
• improved ground/ vegetation cover

3.6 SLM measures comprising the Technology

Comments:

On agricultural fields, ANR is used as an agronomic practice to improve the system of land clearing. It is also a vegetative measure to improve the cover of trees and shrubs. In the pastoral zone, the technology fulfills all these functions, especially the functions to improve the vegetation cover and to produce forage.

3.7 Main types of land degradation addressed by the Technology

Comments:

ANR addresses several types of land degradation which threaten the soil fertility and the production of forage. The practice integrates an enhanced support to the regeneration of plants and vegetation cover with the aim to control the most frequently occurring types of soil erosion in the countries of the Sahel.

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• prevent land degradation
• reduce land degradation

Comments:

Apart from preventing and reducing land degradation, ANR also contributes to the restoration and rehabilitation of degraded land, that otherwise would have required considerable investments. In that case ANR is linked to the closure of certain areas for grazing to enable a full recovery of the land.

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology area

other/ national currency (specify):

West African CFA francs

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

500.0

4.3 Establishment activities

	Activity	Timing (season)
1.	Awareness-raising among the population and demonstrations of ANR techniques in villages	In the dry season, at the start of the project (preferably in January-February)
2.	Set-up of an organisational structure to promote ANR based on village committees, and training of committee members in: identifying, protecting and nurturing seedlings (derived from seeds, tree sprouts, shoots, layers, etc.).	Immediately after the awareness-raising and before the start of the rainy season
3.	Early intervention to enhance the regeneration and treatment of seedlings	At the start of the rainy season, after the establishment of the supervisory committees
4.	Develop vegetative propagation of species with potential for ANR	During the rainy season

Comments:

These activities are part of the implementation of a development project. If ANR is implemented spontaneously, the agropastoralist or livestock keeper directly initiates ANR without an awareness campaign or supervisory committee in place.

4.4 Costs and inputs needed for establishment

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	skilled labour	person-days	1.0	21000.0	21000.0
Labour	unskilled labour	person-days	14.0	1500.0	21000.0	100.0
Equipment	Small equipment (machete, hoe, short-handled hoe, etc.)	set	1.0	3000.0	3000.0	100.0
Total costs for establishment of the Technology					45000.0
Total costs for establishment of the Technology in USD					90.0

If land user bore less than 100% of costs, indicate who covered the remaining costs:

In case the implementation of the technology was conducted in the context a development project, only the costs of training are not borne by the land user, but covered by the project. In some cases the project also provides technical support, such as the installation of a tree nursery or food distribution.

Comments:

The total costs are indicated for the establishment of ANR through a development project. When the land user accomplishes ANR himself, the costs are 24.000 CFA francs/hectare, that is the costs for labour and depreciation of equipment. Labour costs represent almost 90% of the total costs for establishment of the technology. The costs for installation of a nursery are not included in the cost calculations. In the strict sense, ANR is not combined with the production of nursery plants.

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Base pruning: meaning cutting a tree close to the soil surface to encourage sprouts to shoot.	Before the start of the rainy season, during the period from March to May.
2.	2.Pruning trees: comprising cutting off excess and weak branches.	Tree pruning must be performed right after the establishment of crops.
3.	3.Trellising: involving driving one or more posts into the ground to support the selected shoot.	During the rainy season.
4.	4.In agricultural areas, protecting species which are palatable, and species which are not resistant to grazing.	Throughout the rainy season until the crop harvesting.

Comments:

Maintenance work is generally performed by the land users. On sylvo-pastoral land maintenance is carried out by the community and continues throughout the year, but it is most important in the period with precipitation. In the pastoral zone transhumant livestock keepers and nomadic people maintain the technology on an individual basis. In this region, maintenance involves optimizing the use of available forage resources, livestock rotation, and monitoring of the grazing land to enhance the natural regeneration of palatable vegetation species.

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Unskilled labour	person-days	34.0	1500.0	51000.0	100.0
Equipment	Small equipment (hoe, machete, short-handled hoe)	set	1.0	3000.0	3000.0	100.0
Total costs for maintenance of the Technology					54000.0
Total costs for maintenance of the Technology in USD					108.0

If land user bore less than 100% of costs, indicate who covered the remaining costs:

0

Comments:

The maintenance costs exceed the costs for establishment of the technology due to the efforts to secure the ownership of treated land throughout the year. Labour accounts for the major share of the costs. Operations are more intensive during maintenance compared to establishment of the technology. The production of nursery plants is not included in the cost estimation.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour is the key determinant of the costs for establishment and maintenance of the technology, representing almost 90% of the total costs.

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

The topography of the intermediate Sahelian-Saharan strip includes dunes alongside valleys, which are fairly covered with woody vegetation in the part bordering the Sahelian zone. The Sahelian zone has multiple plains and valleys, glacis/plateaus and hills which are crossed by the river Niger in the southwestern part (550 km in Niger), and by several other streams.

5.3 Soils

5.4 Water availability and quality

Is water salinity a problem?

No

Is flooding of the area occurring?

No

Comments and further specifications on water quality and quantity:

The depth of groundwater tables in the pastoral zone is well over 100 m and may frequently reach 500 m or more in the western part (Tchintabaraden). Surface water consists of temporary ponds. In the agro-pastoral zones in the south, groundwater is at more than 100 m depth. In the valleys and plains, groundwater is often found at less than 5 m depth. This zone is characterized by several permanent and ephemeral water courses.

5.5 Biodiversity

Comments and further specifications on biodiversity:

Niger has been one of the main reservoirs of biodiversity in Africa. Over the past five decades, the accelerated degradation of ecosystems has significantly reduced the biodiversity. The degradation is the result of successive droughts and a process of accelerated desertification on the one side, and of population growth leading to a significant pressure on natural resources and/or land on the other side. Several species of vegetation and wildlife have disappeared, while others are in danger of extinction in the coming years despite the national strategies for conservation, protection and restoration implemented by the government authorities and their development partners.
Several restrictions were observed with regard to the management of biodiversity in Niger: (i) insufficient knowledge on biodiversity and biodiversity components, (ii) a lack of specific programs and projects related to biodiversity, (iii) inappropriate legislation on biodiversity, (iv) the failure to involve the populations in the management of biodiversity, (v) insufficient and inappropriate awareness raising, information campaigns and training, (vi) the lack of consideration given to biodiversity in the design and implementation of development measures, (vii) adverse climate conditions, (viii) multiple and increasing pressures on biodiversity and its components, (ix) a high population growth with an uneven spatial distribution, not corresponding to the land capability of the different areas, (x) difficult access to certain isolated regions and regions with steep slopes, (xi) difficult access to water due to topographical and geological constraints.

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Since the late 1990s accelerated urbanization has occurred in the pastoral zone. On the one side, sequential droughts have turned several livestock keepers into simple herders, whereas others preferred to leave the pastoral zone to start new activities in the urban centres. On the other side, the high population growth has forced several families to settle and to diversify their economic activities. Agriculture is increasingly developing beside pastoralism. Similarly, while local populations in the agro-pastoral zone in the south are adapting to climate change, this process has led them to diversify their economic activities. They are increasingly moving towards off-farm activities such as trade. Poor or vulnerable people represent most of the population in all these regions, or almost 60% of the total population. Extremely poor people represent nearly 30% of the total population. The laws on pastoralism are founded on a community-based management of natural resources in the pastoral zone. But since the late 2000s private ranches appeared in this area. The settlement of population groups is leading to the issuing of titles on private land and to land fragmentation around rapidly developing urban centres. Production systems are based on human capital and traditional basic equipment; animal traction is widely used, mainly in the horticultural sector (the camel being the primary animal used for water pumping). Women rarely participate in the production; young and middle-aged men who offer their labour force are the main workers. It should be noticed that among the Tuareg and Bororo Peulh people children drive herds to the grazing areas. In the agro-pastoral zones in the south, men and women work in the fields and perform livestock activities and trade. In these regions children are working from the age of 5. By working in the fields, they provide labour to their parents. There is no process of mechanization in the production systems. Production activities are usually managed in the context of households which function as basic family businesses.

5.7 Average area of land used by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• state
• communal/ village

Land use rights:

• communal (organized)
• individual

Water use rights:

• communal (organized)
• individual

Comments:

The use of communal land for pastoralism is regulated by the laws on pastoralism, which are an integral part of the rural code of Niger. Land in the pastoral zone is owned by the communities and by the State. The pumping stations, drill holes and pastoral wells are the main sources of water supply in the pastoral zone. This infrastructure generally remains the property of the State, and is placed under the responsibility of the municipalities. There is also privately owned infrastructure (wells and drill holes). In contrast, land ownership in the agro-pastoral zone in the south is typically private (with and without land title deeds); there is some communal land that is regulated by the rural code. Land use rights are usually individual (family rights). Water use rights are mostly individual and organized at the level of the community.

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Socio-cultural impacts

Ecological impacts

Soil

Biodiversity: vegetation, animals

Climate and disaster risk reduction

6.2 Off-site impacts the Technology has shown

Specify assessment of off-site impacts (measurements):

The impact assessment is mainly based on observations from the regions of Maradi (department of Maradi), Tillabéri (departments of Kollo and Abala) and Tahoua (departments of Abalak and Tchintabaraden). The impact of ANR is limited in the short term. However, in the medium and long term the effects are highly significant both with regard to vegetation cover and to the development of woody species. Hence the technology is very sensitive to climate change, which reduces the ecological and economic impacts.

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change

	Season	increase or decrease	How does the Technology cope with it?
annual temperature		increase	not well
seasonal temperature	dry season	increase	not well
annual rainfall		decrease	not well
seasonal rainfall	wet/ rainy season	decrease	not well

Climate-related extremes (disasters)

Meteorological disasters

	How does the Technology cope with it?
local sandstorm/ duststorm	moderately
local windstorm	moderately
tornado	moderately

Climatological disasters

	How does the Technology cope with it?
drought	not well

Other climate-related consequences

Other climate-related consequences

	How does the Technology cope with it?
reduced growing period	moderately

Comments:

According to all land users, ANR remains very sensitive to gradual change and to extreme events or disasters related to climate change, both in the pastoral zone and in the agro-pastoral regions in the south. The high variability of precipitation has negatively influenced the impact of ANR in all regions in Niger.

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

Comments:

The establishment and maintenance costs of ANR are very low. Therefore the short-term returns are still slightly positive. In the pastoral zone observations show positive returns of the technology, even in the short term. The impacts are clearer in the medium and long term, and the cost-effectiveness is highest at these time scales.

6.5 Adoption of the Technology

• 11-50%

If available, quantify (no. of households and/ or area covered):

The majority of transhumant livestock keepers in the pastoral zone (60%) have adopted ANR over an area of approximately 2,000 km2 of grazing land. In the agro-pastoral zone within the regions of Tillabéri, Maradi and Tahoua the area treated with ANR exceeds 10,000 km2

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?

• 91-100%

Comments:

Most development projects implementing ANR do not provide material or financial incentives. In the pastoral zone the technology must be applied in conditions without external support by relying on local know-how.

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

Yes

If yes, indicate to which changing conditions it was adapted:

• climatic change/ extremes

Specify adaptation of the Technology (design, material/ species, etc.):

Several projects have adapted ANR by complementing the implementation with tree planting and seeding local or external forage species in sylvo-pastoral land. Some projects have combined the technology with the control of invasive plant species and plants that are harmful to livestock. ANR is based on the selection of species that have high potential for the production and marketing of forage and timber.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
The strength of ANR is that the technology is easy to implement and maintain, and therefore entails very low costs. This has led to the widespread adoption of the technology in all regions.
The second strength is the improvement of soil fertility and the increase of crop and fodder yields. The improved soil fertility leads to an increase in production and improved food security, both for humans and livestock.
The third strength is that resources are being renewed, and that needs for timber and forage are met. According to land users, these supplementary resources enable them to improve their living standards.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The ease of adoption, which has enabled the dissemination of the technology across the country. The technology is a local innovation, which was disseminated and scaled-up by development projects. The implementation and maintenance are in line with the project cycle.
The effect of ANR in reducing the evaporation of soil moisture is a major strength in a Sahelian country like Niger. The ANR technology has positive impacts on the vegetation cover, the soil biodiversity and the density of woody vegetation. These constitute a major advantage in a region subject to accelerated desertification and to the effects of almost chronic droughts.
Conservation and restoration of the environment through ANR are a major advantage in this region of the Sahel, which faces accelerated environmental degradation due to human activities and climate change.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view	How can they be overcome?
The impacts of investments in the technology are only significant in the medium and long term. A long period is required to benefit from the results.	Land users should be supported by implementing the technology in the first year in which ANR is adopted, in the form of cash or food for work.
The technology requires that tenure of fields and sylvo-pastoral land are secure.	Establishing community-based brigades to supervise the land under treatment.

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Illegal logging both in the fields and in the grazing areas.	Establish a communal system to supervise treated areas in partnership with all stakeholders.
Lack of a monitoring mechanism and of guidelines for the rational use of resources.	The land commissions at the local level and at the level of villages or tribes should be supported to establish community-based mechanisms to supervise and monitor the implementation of laws on pastoralism, and of the rural code in general.
Lack of legislation on forestry incorporating the status of regenerating trees in fields and in the pastoral zone.	The legislation in force should be adapted to the context resulting from the implementation of ANR in fields and in the pastoral zone.

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Valoriser les produits du palmier doum pour gérer durablement le système agroforestier d'une vallée sahélienne du Niger et éviter sa désertification, Peltier Régis, Claudine Serre Duhem and Aboubacar Ichaou, 2008

Available from where? Costs?

document available for download on the Internet

Title, author, year, ISBN:

Note de capitalisation « Expérience du Programme Niger FIDA dans la mise á l’échelle de la Régénération Naturelle Assistée (RNA) », PASADEM, 2015

Available from where? Costs?

PASADEM, GREAD

Title, author, year, ISBN:

Etude de Cas: Régénération Naturelle Assistée (RNA) dans la région de Maradi (Niger), Abdoulaye Sambo Soumaila, 2015

Available from where? Costs?

GREAD

7.3 Links to relevant online information

Title/ description:

aucun lien

URL:

aucun lien